1. Field of the Invention
This invention concerns containers designed to be filled with a liquid. More particularly the invention relates to an air vent device in a container with a sealed closure subjected to uncontrolled oscillation designed to be filled with a liquid.
2. Description of Related Art
A container of this type is the torpedo tube on board a submarine or any other type of missile launcher. The torpedo tube is submerged, and its operation necessitates balancing the pressure inside the tube with the surrounding environment (i.e., the water) before the two are connected together.
It is then necessary to vent the air from inside the tube as the water fills the tube through a filling orifice. For this purpose, the tube has two vent orifices located one at each end. Each one is associated with a circuit in which an isolating valve and a water presence indicator are placed in series. Any water ingress detected by the water presence indicator results in the closure of the isolating valves. Thus in normal conditions, when the tube is filled with water and the isolating valves have been closed, the tube filled with water at the same pressure as the surrounding environment (the sea) can be opened at one end to allow the torpedo to be launched.
Unfortunately, any change in the attitude of the launcher due to pitch or roll brings about a corresponding inclination of the tube. This inclination may then cause water accidentally to reach one or other of the water presence indicators and result in the closure of the isolating valve resulting in random venting of the air if there is oscillation of the launcher caused mainly by pitching.